How many molecules of water are in 4.93g of water

1.	How many molecules of water are in 4.93g of water
Answer» ANSWER: In order to figure out how many molecules of water are present in that 48.90-g sample, you first need to determine how many MOLES of water you have there. As you know, a mole is SIMPLY a very large collection of molecules. In order to have one mole of something, you need to have exactly 6.022 ⋅ 10 23 molecules of that something - this is KNOWN as AVOGADRO's number. In order to get to moles, you must use water's molar mass. A substance's molar mass tells you the mass of one mole of molecules of said substance. Water has a molar mass of 18.015 g/mol . This means that one mole of water molecules has a mass of 18.015 g . So, to sum this up, 6.022 ⋅ 10 23 molecules of water will amount to 1 mole of water, which in turn will have a mass of 18.015 g .

Answer»

In order to figure out how many molecules of water are present in that

48.90-g

sample, you first need to determine how many MOLES of water you have there.

As you know, a mole is SIMPLY a very large collection of molecules. In order to have one mole of something, you need to have exactly

6.022

⋅

molecules of that something - this is KNOWN as AVOGADRO's number.

In order to get to moles, you must use water's molar mass. A substance's molar mass tells you the mass of one mole of molecules of said substance.

Water has a molar mass of

18.015 g/mol

. This means that one mole of water molecules has a mass of

18.015 g

So, to sum this up,

6.022

⋅

molecules of water will amount to

1 mole

of water, which in turn will have a mass of

18.015 g

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